Duplex envelope



Dec. 7, 1937. c. F. PFLANZE DUPLEX ENVELOPE Filed March 9, 1956 Patented Dec. 7, 1937 UNTED STTES PATENT OFFICE 1 Claim.

My invention contemplates a duplex envelope consisting of a relatively small envelope container to hold a letter and a relatively large envelope container to hold printed matter, said containers being adapted to be connected together, and a1- though subject to diiferent postal rates, the smaller envelope being adapted to Vbe enclosed within the larger envelope when transmitted through the mails in such manner that the small envelope may, if desired, be sealed against inspection and the large envelope remain unsealed.

Heretofore structures of this character have involved expensive preparation or expensive manipulation, or both, thereby necessitating an undue or excessive cost element which was objectionable in the utilization of duplex envelopes. The object of my invention, therefore, is to provide an improved construction and simple arrangement, whereby things which are subject to diierent postal rates and which are usually sent in separate envelopes or wrappers may be enclosed to all intents and purposes in practically one and the same envelope, so that the two things may not become separated and will arrive at their destination together.

Another object of my invention is to provide the small and large envelopes with window' openings adapted to register with each other, which registration is easily accomplished prior to the joining of the two envelopes together. Such joinder may be done at any time prior to mailing, and with the assurance that a complete registration of the window openings will be had in a simple and efcient manner. By my'arrangement, a duplex envelope may be produced at a minimum of expense and with a maximum of eiciency.

With the foregoing and other objects in view, the invention comprises the novel construction, combination, and arrangement of parts as hereinafter more specifically described and illustrated in the accompanying drawing, wherein is shown an embodiment of the invention, but it is to be understood that changes, variations, and modications can be had which will come within the scope of the claim hereunto appended.

Fig. l is a front elevation of my duplex envelope, with a portion of the front wall broken away to show the construction.

Fig. 2 is a rear elevation of my duplex envelope showing the flaps of the large and small envelopes open, and the location of the small envelope in relation to the large envelope, part of the rear Wall being broken away to show the construction.

Fig. 3 is a rear elevation of the small envelope adapted to be contained in the Alarge envelope.

Fig. 4 is an enlarged, vertical section taken on line 4--4 of Fig. l.

As thus illustrated, the invention comprises an envelope it of any suitable form or character having one end or side thereof provided with a closure iiap Il, said flap to be secured in place either by intucking or by the usual fastening device, or by any suitable means. The front wall of the envelope I Il is provided with a longitudinal window opening i2 of rectangular shape, which is preferably provided with a transparent slip I3, or such transparency may be provided in any usual and well known manner, such as by treating the envelope with a preparation to render it transparent at the desired point. The purpose of providing the transparent slip in the envelope Ill at the rectangular opening I2 is to avoid a rough edge which might subject the outer envelope to a tearing action if said opening were not protected in this manner.

A small envelope I4, which may be of any convenient size and shape, is provided with the usual ap I5 coated with the usual adhesive I6 at its outer edge. A rectangular window Il is provided longitudinally in the rear face of the smaller envelope I4 and is preferably protected by a transparent slip I8, or such transparency may be provided by the application of a preparation to the paper to render the same transparent in the usual and well known manner. The rectangular window II in the envelope I4 is adapted to register with the rectangular window I2 in the envelope I0 when the two envelopes are joined together to make a duplex envelope. After the smaller envelope I4 is positioned within the envelope I0 as shown in Fig. 2, the envelope I4 may be secured to the front wall of the envelope ID by a strip of adhesive I9 placed on the back of the envelope I4 at the upper portion of the rear wall of said envelope, and when attached to the front wall of the envelope Ill it appears as shown in Fig. 1.

It will be understood, of course, that the utilization of the adhesive strip I9 is entirely discretionary, and the utilization of the transparent slip I8 in the envelope I4 is also discretionary.

The two envelopes Ill and I4 are brought together when it is desired to join the two in a duplex envelope, and the person manipulating the same adjusts the envelope I4 in the envelope I0 so as to cause the longitudinal, rectangular Window openings I2 and I1 to register, and then the adhesive strip I6 on the envelope I4 is moistened and said envelope secured by its ap I5 to the flap II of the envelope I0, and the duplex envelope is assembled ready for use. The firstclass mail is placed in the envelope I4 with the name and address showing through the longitudinal, rectangular window opening I'I, and by virtue of the registration of the Window I'I in the envelope I4 with the longitudinal window I2 in the envelope II), the name and address are discernible through both envelopes. If the adi hesive strip I9 on the envelope I4 is to be employed, this strip is then moistened and the envelope I4 securely attached to the inner side of the front Wall of the envelope I9, and thus the contents of the envelope I4 are closed against inspection. The other matter to be placed in the envelope IG is then inserted so that said matter is between the envelope I4 and the rear Wall of the envelope Iil, thus holding said envelope I4 securely in position. The ap II may then be infolded or secured in any desired manner so that the contents of the envelope I0 may be subject to inspection.

It will be noted that by my construction the assembly of the duplex envelope may take place at the time the envelopes are being employed and just prior to mailing, or if desired these envelopes may be assembled in quantities and the rst-class matter may be inserted in the envelope I4 by bending said envelope upwardly and outwardly from the envelope i0, and after the insertion of said first-class matter in said envelope I4 it is again returned vto its position in the envelope I0, as shown in Fig. 2. By this arrangement a duplex envelope is obtained requiring a minimum amount of manipulation both in preparation of the materials and the joinder of said materials in a composite envelope, and at a minimum of expense.

It is thought the many advantages of my improved duplex envelope in accordance with this invention can be readily understood, and a1- though the preferred embodiment of the invention is as illustrated and described, yet it is to be understood that changes in the details of construction can be had which will fall Within the scope of the invention as claimed.

I claim:

A duplex envelope comprising a relatively large rectangular compartment for printed matter requiring less than first-class postage, provided with a closure flap and a Window on the same side as said closure flap, and a relatively small, rectangular letter compartment also provided with a closure ap, said latter closure ap being secured on the inside of the closure ap of said large compartment prior to closure of said large compartment, said small letter compartment having a window in one side thereof opposite the side to which the said closure flap is secured, said Windows in both the large and small compartments registering with each other so that one address applied to the small compartment is sufficient for both kinds of mail matter, means n for accessibly closing the large compartment, means for holding said small compartment against the inner front Wall of the large compartment, substantially as described.

CHARLES F. PFLANZE. 

